Enable Nexus by default (#7021)

## What changed?

- Change the `system.enableNexus` dynamic config default to `true`.
- Remove test overrides for that dynamic config.
- Return false for Nexus enabled in `GetSystemInfo` if the HTTP server
is disabled.

common/dynamicconfig/constants.go

@@ -861,9 +861,9 @@ and deployment interaction in matching and history.`,
 	)
 	EnableNexus = NewGlobalBoolSetting(
 		"system.enableNexus",
-		false,
-		`EnableNexus toggles all Nexus functionality on the server. Note that toggling this requires restarting
-server hosts for it to take effect.`,
+		true,
+		`Toggles all Nexus functionality on the server. Note that toggling this requires restarting server hosts for it
+		to take effect.`,
 	)
 	RefreshNexusEndpointsLongPollTimeout = NewGlobalDurationSetting(
 		"system.refreshNexusEndpointsLongPollTimeout",

service/frontend/fx.go

@@ -681,6 +681,8 @@ func OperatorHandlerProvider(
 }
 
 func HandlerProvider(
+	cfg *config.Config,
+	serviceName primitives.ServiceName,
 	dcRedirectionPolicy config.DCRedirectionPolicy,
 	serviceConfig *Config,
 	versionChecker *VersionChecker,
@@ -733,6 +735,7 @@ func HandlerProvider(
 		membershipMonitor,
 		healthInterceptor,
 		scheduleSpecBuilder,
+		httpEnabled(cfg, serviceName),
 	)
 	return wfHandler
 }
@@ -794,6 +797,15 @@ func MuxRouterProvider() *mux.Router {
 	return mux.NewRouter().UseEncodedPath()
 }
 
+func httpEnabled(cfg *config.Config, serviceName primitives.ServiceName) bool {
+	// If the service is not the frontend service, HTTP API is disabled
+	if serviceName != primitives.FrontendService {
+		return false
+	}
+	// If HTTP API port is 0, it is disabled
+	return cfg.Services[string(serviceName)].RPC.HTTPPort != 0
+}
+
 // HTTPAPIServerProvider provides an HTTP API server if enabled or nil
 // otherwise.
 func HTTPAPIServerProvider(
@@ -810,15 +822,10 @@ func HTTPAPIServerProvider(
 	logger log.Logger,
 	router *mux.Router,
 ) (*HTTPAPIServer, error) {
-	// If the service is not the frontend service, HTTP API is disabled
-	if serviceName != primitives.FrontendService {
+	if !httpEnabled(cfg, serviceName) {
 		return nil, nil
 	}
-	// If HTTP API port is 0, it is disabled
 	rpcConfig := cfg.Services[string(serviceName)].RPC
-	if rpcConfig.HTTPPort == 0 {
-		return nil, nil
-	}
 	return NewHTTPAPIServer(
 		serviceConfig,
 		rpcConfig,

service/frontend/workflow_handler.go

@@ -145,6 +145,7 @@ type (
 		healthInterceptor               *interceptor.HealthInterceptor
 		scheduleSpecBuilder             *scheduler.SpecBuilder
 		outstandingPollers              collection.SyncMap[string, collection.SyncMap[string, context.CancelFunc]]
+		httpEnabled                     bool
 	}
 )
 
@@ -173,6 +174,7 @@ func NewWorkflowHandler(
 	membershipMonitor membership.Monitor,
 	healthInterceptor *interceptor.HealthInterceptor,
 	scheduleSpecBuilder *scheduler.SpecBuilder,
+	httpEnabled bool,
 ) *WorkflowHandler {
 
 	handler := &WorkflowHandler{
@@ -225,6 +227,7 @@ func NewWorkflowHandler(
 		healthInterceptor:   healthInterceptor,
 		scheduleSpecBuilder: scheduleSpecBuilder,
 		outstandingPollers:  collection.NewSyncMap[string, collection.SyncMap[string, context.CancelFunc]](),
+		httpEnabled:         httpEnabled,
 	}
 
 	return handler
@@ -2922,7 +2925,7 @@ func (wh *WorkflowHandler) GetSystemInfo(ctx context.Context, request *workflows
 			SdkMetadata:                     true,
 			BuildIdBasedVersioning:          true,
 			CountGroupByExecutionStatus:     true,
-			Nexus:                           wh.config.EnableNexusAPIs(),
+			Nexus:                           wh.httpEnabled && wh.config.EnableNexusAPIs(),
 		},
 	}, nil
 }

service/frontend/workflow_handler_test.go

@@ -197,6 +197,7 @@ func (s *WorkflowHandlerSuite) getWorkflowHandler(config *Config) *WorkflowHandl
 		s.mockResource.GetMembershipMonitor(),
 		healthInterceptor,
 		scheduler.NewSpecBuilder(),
+		true,
 	)
 }
 
@@ -2069,8 +2070,7 @@ func (s *WorkflowHandlerSuite) TestGetSystemInfo() {
 	s.True(resp.Capabilities.SupportsSchedules)
 	s.True(resp.Capabilities.EncodedFailureAttributes)
 	s.True(resp.Capabilities.UpsertMemo)
-	// Nexus is enabled by a dynamic config feature flag which defaults to false.
-	s.False(resp.Capabilities.Nexus)
+	s.True(resp.Capabilities.Nexus)
 }
 
 func (s *WorkflowHandlerSuite) TestStartBatchOperation_Terminate() {

service/history/tests/vars.go

@@ -184,7 +184,6 @@ func NewDynamicConfig() *configs.Config {
 	config.EnableActivityEagerExecution = dynamicconfig.GetBoolPropertyFnFilteredByNamespace(true)
 	config.EnableEagerWorkflowStart = dynamicconfig.GetBoolPropertyFnFilteredByNamespace(true)
 	config.NamespaceCacheRefreshInterval = dynamicconfig.GetDurationPropertyFn(time.Second)
-	config.EnableNexus = dynamicconfig.GetBoolPropertyFn(true)
 	config.ReplicationEnableUpdateWithNewTaskMerge = dynamicconfig.GetBoolPropertyFn(true)
 	config.EnableWorkflowExecutionTimeoutTimer = dynamicconfig.GetBoolPropertyFn(true)
 	config.EnableWorkflowIdReuseStartTimeValidation = dynamicconfig.GetBoolPropertyFnFilteredByNamespace(true)

tests/callbacks_test.go

@@ -195,7 +195,6 @@ func (s *CallbacksSuite) TestWorkflowCallbacks_InvalidArgument() {
 }
 
 func (s *CallbacksSuite) TestWorkflowNexusCallbacks_CarriedOver() {
-	s.OverrideDynamicConfig(dynamicconfig.EnableNexus, true)
 	s.OverrideDynamicConfig(
 		callbacks.AllowedAddresses,
 		[]any{map[string]any{"Pattern": "*", "AllowInsecure": true}},
@@ -337,7 +336,6 @@ func (s *CallbacksSuite) TestWorkflowNexusCallbacks_CarriedOver() {
 }
 
 func (s *CallbacksSuite) TestNexusResetWorkflowWithCallback() {
-	s.OverrideDynamicConfig(dynamicconfig.EnableNexus, true)
 	s.OverrideDynamicConfig(
 		callbacks.AllowedAddresses,
 		[]any{map[string]any{"Pattern": "*", "AllowInsecure": true}},

tests/testcore/client_suite.go

@@ -85,7 +85,6 @@ func (s *ClientFunctionalSuite) SetupSuite() {
 		dynamicconfig.FrontendEnableWorkerVersioningDataAPIs.Key():          true,
 		dynamicconfig.FrontendEnableWorkerVersioningWorkflowAPIs.Key():      true,
 		dynamicconfig.FrontendMaxConcurrentBatchOperationPerNamespace.Key(): ClientSuiteLimit,
-		dynamicconfig.EnableNexus.Key():                                     true,
 		dynamicconfig.RefreshNexusEndpointsMinWait.Key():                    1 * time.Millisecond,
 		callbacks.AllowedAddresses.Key():                                    []any{map[string]any{"Pattern": "*", "AllowInsecure": true}},
 	}

tests/testcore/functional.go

@@ -55,7 +55,6 @@ func (s *FunctionalSuite) SetupSuite() {
 	s.dynamicConfigOverrides = map[dynamicconfig.Key]any{
 		dynamicconfig.RetentionTimerJitterDuration.Key():        time.Second,
 		dynamicconfig.EnableEagerWorkflowStart.Key():            true,
-		dynamicconfig.EnableNexus.Key():                         true,
 		dynamicconfig.FrontendEnableExecuteMultiOperation.Key(): true,
 	}
 	s.FunctionalTestBase.SetupSuite("testdata/es_cluster.yaml")

tests/testcore/functional_test_base.go

@@ -167,7 +167,6 @@ func (s *FunctionalTestBase) SetupSuite(defaultClusterConfigFile string, options
 		dynamicconfig.TaskQueueScannerEnabled.Key():  false,
 		dynamicconfig.ExecutionsScannerEnabled.Key(): false,
 		dynamicconfig.BuildIdScavengerEnabled.Key():  false,
-		dynamicconfig.EnableNexus.Key():              true,
 		// Better to read through in tests than add artificial sleeps (which is what we previously had).
 		dynamicconfig.ForceSearchAttributesCacheRefreshOnRead.Key(): true,
 	})

tests/xdc/nexus_request_forwarding_test.go

@@ -72,9 +72,8 @@ func (s *NexusRequestForwardingSuite) SetupSuite() {
 	s.dynamicConfigOverrides = map[dynamicconfig.Key]any{
 		// Make sure we don't hit the rate limiter in tests
 		dynamicconfig.FrontendGlobalNamespaceNamespaceReplicationInducingAPIsRPS.Key(): 1000,
-		dynamicconfig.EnableNexus.Key():                  true,
-		dynamicconfig.RefreshNexusEndpointsMinWait.Key(): 1 * time.Millisecond,
-		callbacks.AllowedAddresses.Key():                 []any{map[string]any{"Pattern": "*", "AllowInsecure": true}},
+		dynamicconfig.RefreshNexusEndpointsMinWait.Key():                               1 * time.Millisecond,
+		callbacks.AllowedAddresses.Key():                                               []any{map[string]any{"Pattern": "*", "AllowInsecure": true}},
 	}
 	s.setupSuite([]string{"nexus_request_forwarding_active", "nexus_request_forwarding_standby"})
 }

tests/xdc/nexus_state_replication_test.go

@@ -69,9 +69,8 @@ func (s *NexusStateReplicationSuite) SetupSuite() {
 	s.dynamicConfigOverrides = map[dynamicconfig.Key]any{
 		// Make sure we don't hit the rate limiter in tests
 		dynamicconfig.FrontendGlobalNamespaceNamespaceReplicationInducingAPIsRPS.Key(): 1000,
-		dynamicconfig.EnableNexus.Key():                  true,
-		dynamicconfig.RefreshNexusEndpointsMinWait.Key(): 1 * time.Millisecond,
-		callbacks.AllowedAddresses.Key():                 []any{map[string]any{"Pattern": "*", "AllowInsecure": true}},
+		dynamicconfig.RefreshNexusEndpointsMinWait.Key():                               1 * time.Millisecond,
+		callbacks.AllowedAddresses.Key():                                               []any{map[string]any{"Pattern": "*", "AllowInsecure": true}},
 	}
 	s.setupSuite([]string{"nexus_state_replication_active", "nexus_state_replication_standby"})
 }